270 



NEW ENGLAND FARMER. 



June 



When this action does not take place, an excess 

 of carbonic acid may render soil unproductive, but 

 it always improves it in richness that may at any 

 time be made available for cultivation by simple 

 exposure to the air, or by the action of alkalies. 

 An excess of carbonic acid is rarely to be found 

 unless in undrained lands. 



Ammonia is thought to produce no effect upoH 

 plants through the agency of the atmosphere, but 

 to act upon them from the soil alone. Ammonia 

 is collected from the atmosphere by rains and 

 dews, and acts upon soils as an alkali, neutraliz- 

 ing acids, and decomposing silex, forming com- 

 pounds soluble in water. Though this gas forms 

 but one twenty-eight-millionth part of the atmos- 

 phere, it is of the very highest importance in the 

 formation of productive soils. But as its action 

 in this case is intimately connected with that of 

 rains, dews and changes of temperature, it will 

 not be considered as an independent agent, as- 

 suming that its effect is included within that of 

 weathering. 



By the term weathering I mean to express such 

 action as temperature, rain, dew and aeration 

 may have upon any formation, the time within 

 which it has taken place being unlimited. 



The following table and remarks by Stockhardt 

 illustrate, in a very forcible manner, the action of 

 rain and change of temperature in producing the 

 stratification of soils. "Basalt, an intimate mix- 

 ture of felspar and augite, exhibited the following 

 differences in a comparison of its constituents in 

 the fresh and weathered condition : 



The first thing resulting, with gi-eat clearness, 

 from these figures, is the diverse degrees of solu- 

 bility of the individual constituents of basalt ; the 

 fresh, solid basalt had lost approximately by its 

 ■weathering, of its 



Alumina 



Peroxide of iron l-40th. 



Silica l-5th. 



Alkaline earths, (lime and magnesia) l-3d. 



Allialies, (potash and soda) 2-3ds. 



If we have to regard those constituents which 

 have been lost in the greatest proportion as the 

 most easily soluble, those lost in the smallest 

 quantity as the most difficult of solution, it fol- 

 lows that the alkalies pass into solution first and 

 most abundantly in weathering, next the alkaline 

 earths, and then the silica." 



Assuming that the same action will take place 

 in the weathering of a soil derived from granite 

 rock, the analysis of which is 



Alumina 12.99 lbs. 



Oxide of iron 1.96 " 



Silica 75.86 " 



Alkaline earths, lime, magnesia and manganese 1.59 " 



Alkalies, potash and soda 7.60 " 



100.00 lbs. 



After a certain amount of weathering the anal- 

 ysis would be as follows, supposing that tlie soil 

 is so situated that its soluble portion is removed 

 by a sui'plus of water : 



Alumina 16.41 lbs. 



Oxide (JTiron 2.42 " 



Silica 76.65 " 



Alkaline earths 1 .33 " 



Alkalies 3.19 " 



100.00 lbs. 



Again, instead of supposing the soil to lose a cer- 

 tain portion of its soluble matter, we suppose it 

 to be so placed that it shall receive the same por- 

 tion that in the former case we had conceived it to 

 have lost, analysis will then give, 



Alumina 10.75 lbs. 



Oxido of iron 1 .66 " 



Silica 75.35 " 



Alkaline earth 1.76 " 



Alkalies 10.48 « 



100.00 lbs. 



Though the above are but supposed cases, yet 

 action and results of precisely the same nature are 

 constantly occurring. Thus, at the top of a hili the 

 soil is constantly losing its soluble portion, on its 

 gentler slopes near the bottom it may receive as 

 much as it loses, and thus remain constant. The 

 valley at its foot will gain in its most soluble part 

 as it receives all that the hill-top loses. For con- 

 venience of reference the analyses are here given 

 together in one table : 



Hill top. Middle ground. Valleif. 



Alumina 16.41 lbs. 12.99 lbs. 10.75 'lbs. 



O.xideofiron 2.42" 1.96" 1.66" 



Silica 76.65" 75.86" 75.,35 " 



Alkaline earths 1.33 " 1.59 « J.76 " 



Alkalies 3.19" 7.60" 10.48" 



100.00 lbs. 100.00 lbs. 100.00 lbs. 



The last table illustrates clearly the effect of 

 weathering upon soils, and explains why analyses, 

 may show great diversity of composition upon the 

 same farm, and where it is evident that the soils 

 all came from the same original rock. It also, to 

 a certain extent, explains the division of the sur- 

 face strata into soil, subsoil and pan ; the part 

 lying nearest the air being more and differently 

 affected than that lower down, in a short time be- 

 comes quite distinct in composition and texture. 



Inspection of the last table will also show that 

 soluble ingredients are alwaj-s increasing in the 

 valleys and diminishing on the hills ; thus, in the 

 course of time the hills must become barren, un- 

 less protected by imdisturbed vegetation, while 

 the low lands increase in mineral richness year by 

 year. 



Boston, April 16, 1860. 



For the New England Farmer. 



HO"W TO GET A GBEAT CHOP OP 

 POTATOES. 



When any of my neighborf^aise better crops 

 or get them with less labor than I can, I am apt 

 to want to know how they do it. On the other 

 hand, if they have extravagant theories, do a 

 great deal of extra work on their land, fuss a 

 great deal with composting manures, and thor- 

 oughly pulverizing the land, and still do not show 

 any better crops than their neighbors, I am not 

 particularly inquisitive to know or practice their 

 theories. 



Happening a few days ago to be in the cellar of 

 Capt. S. Hayden, of HoUis, I noticed his bins of 

 splendid potatoes, and had the curiosity to inquire 

 how he raised them. He told me tliat ou ground 



